Armoured ring for deflecting a dust-gas flow, in roller grinding mills

ABSTRACT

An armoured ring for deflecting the dust-gas flow at the external edge, of a grinding pan, forming the external upper lateral termination of the trajectory of the material for grinding, in roller grinding mills. The cross section of the armoured ring consists of two trapezoidal shaped figures with their major bases placed together. As a result two surfaces are produced extending outwards and inwards and forming externally and internally a respective projecting edge.

United States Patent 1 [1 1 3,905,559

Brundiek Sept. 16, 1975 [5 1 ARMOURED RING FOR DEFLECTING A [56] References Cited DUST-GAS FLOW, IN ROLLER GRINDING FOREIGN PATENTS oR APPLICATIONS MILLS 927,966 5/1955 Germany 24l/58 Inventor: Horst Brundiek, Kaarst, Germany Assignee: Loesche Hartzerkleinerungs -und Zementmachinen KG, Dusseldorf, Germany Filed: Feb. 19, 1974 Appl. No.: 443,792

Foreign Application Priority Data Feb. 28, I973 Germany 2309900 US. Cl 241/59; 241/110 Int. Cl. B02C 15/00; BOZC 23/34 Field of Search 241/52, 53, 58, 59, 110, 241/] 17 Primary E.raminerRoy Lake Assistant Examiner-E. F. Desmond Attorney, Agent, or Firm-Holman & Stern 5 7 ABSTRACT An armoured ring for deflecting the dust-gas flow at the external edge, of a grinding pan, forming the external upper lateral termination of the trajectory of the material for grinding, in roller grinding mills. The cross section of the armoured ring consists of two trapezoidal shaped figures with their major bases placed together. As a result two surfaces are produced extending outwards and inwards and forming externally and internally a respective projecting edge.

8 Claims, 5 Drawing Figures 10):: I- V) v FATENIEB 3,905,559

SHKET 1 [1f 3 PATENTED SEP 1 6 I975 SHEET 2 OF 3 PATENTED SEP 1 61975 SHEET 3 BF 3 ARMOURED RING FOR DEFLECTINGA DUST-GAS FLOW, IN ROLLER GRINDING MILLS BACKGROUND OF. INVENTION a deflection of the air current orflow with the particles of material for grinding, they are liable to a particularly high degree of mechanical wear. Therefore, in the prior art they have to be made of a wear-resistant and particularly expensive material. j

SUMMARY OFjlNivliNTlON I One object of the present invention is that of developing an armoured ring for deflecting a dust-gas-current and which can be produced atre'asonable cost and offers advantages, more particularly from the process point of view, by beingable to be used in different constructional lengths so that the service life until replacement owing to wear-can be substantially increased.

The present invention comprises an'armoured ring for deflecting the dust gas flow atthe external edge, of a grinding pan. forming the external upper lateral termination of the trajectory of the material for grinding, in roller grinding mills, characterised in that the cross section of the armoured ring consists of two trapezoidal shaped figures with their.major bases placed together, and as a result two surfaces are produced extending outwards and inwards and forming externally and internally a respective projecting edgefln this respect it is not, however, of decisive importance forthe trapezoidal shaped surfacesused to be mathematically exact trapezoidal shaped surfaces, because, for example, the various edges can also be made soas to be rounded off. It is of importance this respect that two surfaces respectivcly are produced which extend or project outwards and inwards and which externally and internally each form a projecting edge. However, the surfaces can as such also be curved or vaulted. The armoured ring has holes for receiving screw means. which end above and below in recesses, whose diameters are greater than the diameter of the holes. The armoured ring can be constructed symmetrically in cross section with reference to the bolt or pin axis. In the case of one embodiment of the invention the armoured ring consists of individual parts or segments which can be juxtaposed. The upper trapezoidal shaped figure of the cross-sectional surface of the armoured ring can have a lesser height than the lower trapezoidal shaped figure so that the edge projecting outwards and inwards, of the armoured ring is located in the upper half of the cross section. Furthermore, the upper trapezoidal shaped figure can have a greater height than the lower trapezoidal shaped figure. In the case of a further embodiment of the invention, the end surfaces of the armoured ring segment are placed obliquely in such a manner that on juxtaposition or assemblyan arrangement with a curvature to the left or a curvature to the right respectively is produced. It is, however, also possible to construct the end faces in such a manner that they have a double oblique arrangement or chamfering with in each case the same angle of slope so that they can be assembled or juxtaposed selectively to form an arrangement with a curvature to the right or to the left.

Onetechnical advance in accordance with the invention resides in that-the armoured ring or the individual armoured ring segments respectively on both sides have wear surfaces with aprojecting edge. This offers the possibility of achieving a substantially longer period of wear, that is to say a higher wear resistance for an armoured ring. When the armoured rings consist of individual segments there is the advantage that each segment can be turned about its vertical center axis through as soon as the armoured ring edge is worn onesidedly, that is to say on the edge which was on the inner side of the armoured ring. By turning the segment, it is therefore possible to make use of the nonworn edge. Furthermore, it is possible for each segment to be turned through 180 about its horizontal longitudinal axis so that the lower trapezoidal shaped surface lies at the bottom, the projecting edge lies at a lower level and the angle of inclination with reference to the gas arriving is varied. The inclination is increased when the small trapezoidal shaped figure lies at the bottom so that a sharper deflectionof the gas is achieved. This is of importance when the material subject to grinding is thrown out, for example, behind a roller in the form of a strand and a sharper deflection of the gas is necessary in order to throw back the coarse material in a better fashion onto the grinding pan. It can also be convenient only to turn individual segments about their longitudinal axis through 180 in order to'achieve a locally sharper deflection. It is furthermore advantageous that both the turning of the armoured ring segments and replacement respectively can be undertaken with a lower labour requirement.

LIST OF SEVERAL VIEWS OF DRAWINGS An embodiment of the invention is shown in the accompanying drawings showing application in-a roller mill. I

FIG. 1 shows diagrammatically :the arrangement of the'grinding pan in a roller 'rnillwith armoured ring segments, which'are shown on theleft in section and on the right in elevation.

FIG. 2 shows on a larger scale from the side the other edge of a grinding pan, the grinding rollers being shown diagrammatically, together with a representation of several armoured ring segments.

FIG. 3 shows a sectional view of an armoured ring taken along line IIIIII in FIG. 4.

FIG. 4 shows a view of an armoured ring segment with a representation of the end surfaces which are made oblique on both sides.

FIG. 5 shows two possible arrangements of armoured ring segments.

DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 shows the arrangement of a grinding pan 7 inside a rolling mill with an outer casing 8. During operation rotation of the grinding or milling pan 7 takes place, which at the outer edge has baffles or vanes 9, which form a vane ring arranged as annulus or ring. Above the grinding pan 7 there are two stationarily arranged grinding rollers 11 which can, however, be swung vertically. The vanes 9 produce an air current, which emerges at a high speed at the top part of the vane annulus with the vanes 9 and the material subject to grinding is removed upwards. The sufficiently finely comminuted material subject to grinding on the grinding pan 7 is passed by the gas current to a sifter which is not shown and lies in the upper part of the roller or rolling mill, while the material, which is not yet sufficiently comminuted, that is to say the groats or tails, is

passed along the shortest possible path back to the grinding pan 7. In accordance with the size of the flow angle of an armoured ring 1 the gas flow or current is deflected back to the center of the mill to a greater or lesser extent, as the arrows indicate in FIG. 2. 10 is a channel for the gas flow formed between the outer casing 8 and the grinding pan 7. The manner of operation described within a roller mill, which in the case of mills of this type is always more or less the same, therefore causes a high degree of wear on the armoured ring. The armoured ring is used in all those cases in which a dust-- gas current must be deflected.

FIG. 2 shows on a larger scale those parts of a roller mill, which are located within the ring 12, which has been shown in FIG. I. The representation shows more particularly the deflection of the gas flow at the inwardly arranged projection of the armoured ring.

FIG. 3 shows a cross section of the armoured ring 1, which has a hole 2 for receiving a screw means, which is not shown.

The hole 2 for receiving the screw means is provided below and above with recesses 3 and 4 which serve for receiving the headsof the screw means.

FIG. 4 is a view looking down onto an armoured ring segment 1, whose end faces have double chamfered portions 5 and 6 which have the same angle of inclination.

FIG. 5 shows the possibilities of assembly of an armoured ring made up of individual armoured ring segments 1, which can therefore have a curvature to the right or to the left as may be desired.

I claim:

I. An armoured ring for deflecting the dust-gas flow at the external edge, of a grinding pan, forming the external upper lateral termination of the trajectory of the material for grinding, in roller grinding mills, characterised in that the cross section of the armoured ring conbases placed together, and as aresult two surfaces are produced extending outwards and inwards and forming externally and internally a respective projecting edge. 2. The armoured ring in accordance with claim 1, characterised in that the armoured ring has holes for receiving screw means, which above and below end in recesses. whose diameter is greater than the diameter of the holes.

3. The armoured ring in accordance with claim 2, in.

which the armoured ring is symmetrically constructed in cross section.

4. The armoured '-ring in accordance with claim 1, characterised in that'the armoured ring consists of seg' ments which are adapted to be assembled together.

5. The armoured ring in accordance with claim 1, characterised in that the upper trapezoidal shaped figure of .the cross section of the armoured ring has a smaller height thanthe lower trapezoidal shaped figure so that the edge projecting outwards and inwards of the armoured ring is located in the upper half of the cross section.

6. The armoured ring in accordance with claim 1, characterised in that the lower trapezoidal shaped figure of the cross section of the armoured ring has a smaller height than the upper trapezoidal shaped figure so that the edge projecting outwa'rds and inwards of the armoured ring is located in the lower half of the cross section.

7. The armoured ring in accordance with claim 4, characterised in that the end faces of the armoured ring segment are arranged in such an oblique manner that on putting together in individual segments an arrangement with a curvature to the left or with a curvature to the right is produced.

8. The armoured ring in accordance with claim 4, characterised in that the end face of thearmoured ring segment has a double chamfering with the same angle of inclination so that on putting the segments together a curvature to the right or to the left is produced selectively. I 

1. An armoured ring for deflecting the dust-gas flow at the external edge, of a grinding pan, forming the external upper lateral termination of the trajectory of the material for grinding, in roller grinding mills, characterised in that the cross section of the armoured ring consists of two trapezoidal shaped figures with their major bases placed together, and as a result two surfaces are produced extending outwards and inwards and forming externally and internally a respective projecting edge.
 2. The armoured ring in accordance with claim 1, characterised in that the armoured ring has holes for receiving screw means, which above and below end in recesses, whose diameter is greater than the diameter of the holes.
 3. The armoured ring in accordance with claim 2, in which the armoured ring is symmetrically constructed in cross section.
 4. The armoured ring in accordance with claim 1, characterised in that the armoured ring consists of segments which are adapted to be assembled together.
 5. The armoured ring in accordance with claim 1, characterised in that the upper trapezoidal shaped figure of the cross section of the armoured ring has a smaller height than the lower trapezoidal shaped figure so that the edge projecting outwards and inwards of the armoured ring is located in the upper half of the cross section.
 6. The armoured ring in accordance with claim 1, characterised in that the lower trapezoidal shaped figure of the cross section of the armoured ring has a smaller height than the upper trapezoidal shaped figure so that the edge projecting outwards and inwards of the armoured ring is located in the lower half of the cross section.
 7. The armoured ring in accordance with claim 4, characterised in that the end faces of the armoured ring segment are arranged in such an oblique manner that on putting together in individual segments an arrangement with a curvature to the left or with a curvature to the right is produced.
 8. The armoured ring in accordance with claim 4, characterised in that the end face of the armoured ring segment has a double chamfering with the same angle of inclination so that on putting the segments together a curvature to the right or to the left is produced selectively. 